apes unit 8

Pollutants

Any substance or form of energy introduced into the environment that causes harm to organisms, ecosystems, or human systems (e.g., drinking water supplies, agriculture).

Persistence

How long a pollutant lasts in the environment before it breaks down or is removed.

Mobility

How easily a pollutant moves through the environment (e.g., water-soluble pollutants spreading through groundwater and rivers).

Environmental Transformation

Chemical, microbial, or sunlight-driven changes that convert a pollutant into a less harmful form or a more harmful form.

Methylmercury

A highly toxic, bioavailable form of mercury produced by microbes; strongly biomagnifies in food webs.

Point Source Pollution

Pollution from a specific, identifiable source, often easier to measure and regulate.

Nonpoint-source pollution

Pollution from many diffuse sources over a broad area, harder to regulate because there is no single outflow.

Watershed

The land area that drains water to a common outlet; pollutants released within it can be transported downhill into waterways.

Impermeable surface

A surface that blocks infiltration, increasing runoff and often increasing flooding and pollution transport.

Runoff

Water from rain or snowmelt that flows over land, picking up and transporting pollutants to storm drains and waterways

Urban Runoff

Runoff from cities that can carry oil, metals, sediment, trash, and fertilizers and is often a major driver of flooding and water pollution.

Groundwater Recharge

The process of water infiltrating into the ground to replenish aquifers; reduced by impermeable surfaces, contributing to groundwater depletion

Dissolved oxygen

The amount of oxygen gas dissolved in water; low DO can signal pollution and can lead to stress or death of aquatic organisms

Temperature

A factor affecting water quality because warmer water holds less dissolved oxygen and can increase organisms’ metabolic stress and sensitivity to toxins/disease.

pH

A measure of acidity/basicity; many waters have highest biodiversity near pH 7, and lower pH can increase heavy-metal solubility and toxicity

Turbidity

Cloudiness from suspended particles that scatter light; reduces light penetration, harms photosynthesis, and can damage fish gills

Nutrients

Essential elements at low levels, but in excess can drive algal blooms and major ecosystem changes, often leading to oxygen depletion

Pathogens

Disease-causing organisms that can make people ill and contaminate aquatic food sources like shellfish

Alkalinity

A measure of bicarbonate, carbonate, and hydroxide ions that buffer water against pH change

Coliform Bacteria

Bacteria associated with intestines of warm-blooded animals, their presence suggests possible untreated sewage contamination

Oxygen demanding wastes

Organic materials that decomposers break down while consuming dissolved oxygen

Biochemical oxygen demand

An estimate of biodegradable organic pollution based on how much oxygen microbes require to decompose organic matter in a water sample; high BOD often leads to low DO

Nitrate

A water-soluble nitrogen form commonly from fertilizers; can leach into groundwater or run off to surface waters, promoting algal blooms and DO decline

Phosphate

A phosphorus form from fertilizers/household sources that often adheres to soil particles; erosion and sediment transport are major delivery pathways to water

Sediment pollution

Excess soil in waterways from erosion that increases turbidity, smothers eggs/benthic life, and carries attached pollutants

Thermal pollution

Degradation of water quality by temperature change, which lowers DO and can kill temperature-sensitive species

Eutrophication

Nutrient enrichment that increases plant/algal growth and can trigger downstream oxygen depletion

Cultural eutrophication

Human-caused eutrophication from increased nutrient inputs leading to blooms and hypoxia

Hypoxia

low dissolved oxygen conditions that can cause fish/invertebrates to die or flee; often follows algal bloom die-offs and decomposition

Dead zone

A low-oxygen area, commonly in coastal waters, where many organisms cannot survive due to hypoxia from nutrient-driven decomposition

Harmfull algae bloom

A rapid increase in algae or phytoplankton (sometimes toxin-producing) that raises turbidity and can contribute to oxygen depletion and ecosystem disruption

Pesticide

A chemical used to kill/control pests that can drift, run off, persist, and harm non-target species.

Integrated pest management

reduces reliance on broad chemical use

Pops

Long lasting chemicals that are resistant to breaking down, travel long distances, and can biomagnify

Global distillation effect

Pops evaporating in warm condition, travel through the atmosphere and condense in cold weather

Bioaccumulation

An increase in pollutant concentration within a single organism over time because intake exceeds elimination

Biomagnification

An increase in pollutant concentration at higher trophic levels in a food chain; top predators often have the highest concentrations

Endocrine Disruptors

Chemicals that interfere with hormone systems by mimicking hormones, blocking receptors, or altering hormone production, potentially causing developmental and reproductive effects at low doses.

Heavy Metals

Naturally occurring elements that can be toxic at low concentrations

acid mine drainage

acid runoff formed when exposed minerals react with oxygen and water, dissolving metals into streams

tailings

waste rock, material left after mining

combined sewer overflow

a release of untreated sewage mixed with stormwater when heavy rainfall exceeds that capacity of a combined sewer system

septic system

onsite water treatment using. a tank and a drain field where soil and microbes reduce organic matter and pathogens

Primary treatment

the stage of municipal sewage treatment using screens to remove trash

Secondary Treatment

the biological stage of municipal treatment where microbes break down dissoved organic matter

tertiary treatment

additional stage that targets remaining pollutants, using filtration

clean water act

law that regulates pollutant discharges into surface waters

safe drinking water act

law that regulates contaminated drinking water supplies

resource conservation and recovery act

U.S. law that manages hazardous waste from “cradle to grave,” covering generation through transport, treatment, storage, and disposa

CERCLA

U.S. law that funds and requires cleanup of contaminated sites and assigns liability for hazardous waste releases.